tryserver.chromium.linux: convert chromium_trybot builders to remote_run

scripts/slave/recipes/chromium_trybot.expected/bot_update_failure.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "\nimport sys, os\npath = sys.argv[1]\nmode = int(sys.argv[2])\nif not os.path.isdir(path):\n  if os.path.exists(path):\n    print \"%s exists but is not a dir\" % path\n    sys.exit(1)\n  os.makedirs(path, mode)\n",
-      "[BUILDER_CACHE]/linux_chromium_rel_ng",
+      "[BUILDER_CACHE]/linux",
       "511"
     ],
     "name": "makedirs checkout path",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@python.inline@@@@",
       "@@@STEP_LOG_LINE@python.inline@import sys, os@@@",
       "@@@STEP_LOG_LINE@python.inline@path = sys.argv[1]@@@",
       "@@@STEP_LOG_LINE@python.inline@mode = int(sys.argv[2])@@@",
       "@@@STEP_LOG_LINE@python.inline@if not os.path.isdir(path):@@@",
       "@@@STEP_LOG_LINE@python.inline@  if os.path.exists(path):@@@",
@@ skipping 27 matching lines @@
       "--patchset",
       "1",
       "--rietveld_server",
       "https://codereview.chromium.org",
       "--output_json",
       "/path/to/tmp/json",
       "--revision",
       "src@HEAD",
       "--output_manifest"
     ],
-    "cwd": "[BUILDER_CACHE]/linux_chromium_rel_ng",
+    "cwd": "[BUILDER_CACHE]/linux",
     "env": {
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
     },
     "name": "bot_update",
     "~followup_annotations": [
       "step returned non-zero exit code: 1",
       "@@@STEP_TEXT@Some step text@@@",
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"did_run\": true, @@@",
       "@@@STEP_LOG_LINE@json.output@  \"fixed_revisions\": {@@@",
@@ skipping 79 matching lines @@
       "@@@SET_BUILD_PROPERTY@failure_hash@\"fed620386b0c58ac55d7fd7707794386f73ef90c\"@@@"
     ]
   },
   {
     "name": "$result",
     "reason": "Infra Failure: Step('bot_update') returned 1",
     "recipe_result": null,
     "status_code": 1
   }
 ]